IPVS: fix netns if reading ip_vs_* procfs entries
[linux-2.6/linux-mips.git] / fs / nilfs2 / the_nilfs.c
blobd2acd1a651f31caf260d964c719fed086b43cb85
1 /*
2 * the_nilfs.c - the_nilfs shared structure.
4 * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * Written by Ryusuke Konishi <ryusuke@osrg.net>
24 #include <linux/buffer_head.h>
25 #include <linux/slab.h>
26 #include <linux/blkdev.h>
27 #include <linux/backing-dev.h>
28 #include <linux/random.h>
29 #include <linux/crc32.h>
30 #include "nilfs.h"
31 #include "segment.h"
32 #include "alloc.h"
33 #include "cpfile.h"
34 #include "sufile.h"
35 #include "dat.h"
36 #include "segbuf.h"
39 static int nilfs_valid_sb(struct nilfs_super_block *sbp);
41 void nilfs_set_last_segment(struct the_nilfs *nilfs,
42 sector_t start_blocknr, u64 seq, __u64 cno)
44 spin_lock(&nilfs->ns_last_segment_lock);
45 nilfs->ns_last_pseg = start_blocknr;
46 nilfs->ns_last_seq = seq;
47 nilfs->ns_last_cno = cno;
49 if (!nilfs_sb_dirty(nilfs)) {
50 if (nilfs->ns_prev_seq == nilfs->ns_last_seq)
51 goto stay_cursor;
53 set_nilfs_sb_dirty(nilfs);
55 nilfs->ns_prev_seq = nilfs->ns_last_seq;
57 stay_cursor:
58 spin_unlock(&nilfs->ns_last_segment_lock);
61 /**
62 * alloc_nilfs - allocate a nilfs object
63 * @bdev: block device to which the_nilfs is related
65 * Return Value: On success, pointer to the_nilfs is returned.
66 * On error, NULL is returned.
68 struct the_nilfs *alloc_nilfs(struct block_device *bdev)
70 struct the_nilfs *nilfs;
72 nilfs = kzalloc(sizeof(*nilfs), GFP_KERNEL);
73 if (!nilfs)
74 return NULL;
76 nilfs->ns_bdev = bdev;
77 atomic_set(&nilfs->ns_ndirtyblks, 0);
78 init_rwsem(&nilfs->ns_sem);
79 INIT_LIST_HEAD(&nilfs->ns_dirty_files);
80 INIT_LIST_HEAD(&nilfs->ns_gc_inodes);
81 spin_lock_init(&nilfs->ns_inode_lock);
82 spin_lock_init(&nilfs->ns_next_gen_lock);
83 spin_lock_init(&nilfs->ns_last_segment_lock);
84 nilfs->ns_cptree = RB_ROOT;
85 spin_lock_init(&nilfs->ns_cptree_lock);
86 init_rwsem(&nilfs->ns_segctor_sem);
88 return nilfs;
91 /**
92 * destroy_nilfs - destroy nilfs object
93 * @nilfs: nilfs object to be released
95 void destroy_nilfs(struct the_nilfs *nilfs)
97 might_sleep();
98 if (nilfs_init(nilfs)) {
99 brelse(nilfs->ns_sbh[0]);
100 brelse(nilfs->ns_sbh[1]);
102 kfree(nilfs);
105 static int nilfs_load_super_root(struct the_nilfs *nilfs,
106 struct super_block *sb, sector_t sr_block)
108 struct buffer_head *bh_sr;
109 struct nilfs_super_root *raw_sr;
110 struct nilfs_super_block **sbp = nilfs->ns_sbp;
111 struct nilfs_inode *rawi;
112 unsigned dat_entry_size, segment_usage_size, checkpoint_size;
113 unsigned inode_size;
114 int err;
116 err = nilfs_read_super_root_block(nilfs, sr_block, &bh_sr, 1);
117 if (unlikely(err))
118 return err;
120 down_read(&nilfs->ns_sem);
121 dat_entry_size = le16_to_cpu(sbp[0]->s_dat_entry_size);
122 checkpoint_size = le16_to_cpu(sbp[0]->s_checkpoint_size);
123 segment_usage_size = le16_to_cpu(sbp[0]->s_segment_usage_size);
124 up_read(&nilfs->ns_sem);
126 inode_size = nilfs->ns_inode_size;
128 rawi = (void *)bh_sr->b_data + NILFS_SR_DAT_OFFSET(inode_size);
129 err = nilfs_dat_read(sb, dat_entry_size, rawi, &nilfs->ns_dat);
130 if (err)
131 goto failed;
133 rawi = (void *)bh_sr->b_data + NILFS_SR_CPFILE_OFFSET(inode_size);
134 err = nilfs_cpfile_read(sb, checkpoint_size, rawi, &nilfs->ns_cpfile);
135 if (err)
136 goto failed_dat;
138 rawi = (void *)bh_sr->b_data + NILFS_SR_SUFILE_OFFSET(inode_size);
139 err = nilfs_sufile_read(sb, segment_usage_size, rawi,
140 &nilfs->ns_sufile);
141 if (err)
142 goto failed_cpfile;
144 raw_sr = (struct nilfs_super_root *)bh_sr->b_data;
145 nilfs->ns_nongc_ctime = le64_to_cpu(raw_sr->sr_nongc_ctime);
147 failed:
148 brelse(bh_sr);
149 return err;
151 failed_cpfile:
152 iput(nilfs->ns_cpfile);
154 failed_dat:
155 iput(nilfs->ns_dat);
156 goto failed;
159 static void nilfs_init_recovery_info(struct nilfs_recovery_info *ri)
161 memset(ri, 0, sizeof(*ri));
162 INIT_LIST_HEAD(&ri->ri_used_segments);
165 static void nilfs_clear_recovery_info(struct nilfs_recovery_info *ri)
167 nilfs_dispose_segment_list(&ri->ri_used_segments);
171 * nilfs_store_log_cursor - load log cursor from a super block
172 * @nilfs: nilfs object
173 * @sbp: buffer storing super block to be read
175 * nilfs_store_log_cursor() reads the last position of the log
176 * containing a super root from a given super block, and initializes
177 * relevant information on the nilfs object preparatory for log
178 * scanning and recovery.
180 static int nilfs_store_log_cursor(struct the_nilfs *nilfs,
181 struct nilfs_super_block *sbp)
183 int ret = 0;
185 nilfs->ns_last_pseg = le64_to_cpu(sbp->s_last_pseg);
186 nilfs->ns_last_cno = le64_to_cpu(sbp->s_last_cno);
187 nilfs->ns_last_seq = le64_to_cpu(sbp->s_last_seq);
189 nilfs->ns_prev_seq = nilfs->ns_last_seq;
190 nilfs->ns_seg_seq = nilfs->ns_last_seq;
191 nilfs->ns_segnum =
192 nilfs_get_segnum_of_block(nilfs, nilfs->ns_last_pseg);
193 nilfs->ns_cno = nilfs->ns_last_cno + 1;
194 if (nilfs->ns_segnum >= nilfs->ns_nsegments) {
195 printk(KERN_ERR "NILFS invalid last segment number.\n");
196 ret = -EINVAL;
198 return ret;
202 * load_nilfs - load and recover the nilfs
203 * @nilfs: the_nilfs structure to be released
204 * @sb: super block isntance used to recover past segment
206 * load_nilfs() searches and load the latest super root,
207 * attaches the last segment, and does recovery if needed.
208 * The caller must call this exclusively for simultaneous mounts.
210 int load_nilfs(struct the_nilfs *nilfs, struct super_block *sb)
212 struct nilfs_recovery_info ri;
213 unsigned int s_flags = sb->s_flags;
214 int really_read_only = bdev_read_only(nilfs->ns_bdev);
215 int valid_fs = nilfs_valid_fs(nilfs);
216 int err;
218 if (!valid_fs) {
219 printk(KERN_WARNING "NILFS warning: mounting unchecked fs\n");
220 if (s_flags & MS_RDONLY) {
221 printk(KERN_INFO "NILFS: INFO: recovery "
222 "required for readonly filesystem.\n");
223 printk(KERN_INFO "NILFS: write access will "
224 "be enabled during recovery.\n");
228 nilfs_init_recovery_info(&ri);
230 err = nilfs_search_super_root(nilfs, &ri);
231 if (unlikely(err)) {
232 struct nilfs_super_block **sbp = nilfs->ns_sbp;
233 int blocksize;
235 if (err != -EINVAL)
236 goto scan_error;
238 if (!nilfs_valid_sb(sbp[1])) {
239 printk(KERN_WARNING
240 "NILFS warning: unable to fall back to spare"
241 "super block\n");
242 goto scan_error;
244 printk(KERN_INFO
245 "NILFS: try rollback from an earlier position\n");
248 * restore super block with its spare and reconfigure
249 * relevant states of the nilfs object.
251 memcpy(sbp[0], sbp[1], nilfs->ns_sbsize);
252 nilfs->ns_crc_seed = le32_to_cpu(sbp[0]->s_crc_seed);
253 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
255 /* verify consistency between two super blocks */
256 blocksize = BLOCK_SIZE << le32_to_cpu(sbp[0]->s_log_block_size);
257 if (blocksize != nilfs->ns_blocksize) {
258 printk(KERN_WARNING
259 "NILFS warning: blocksize differs between "
260 "two super blocks (%d != %d)\n",
261 blocksize, nilfs->ns_blocksize);
262 goto scan_error;
265 err = nilfs_store_log_cursor(nilfs, sbp[0]);
266 if (err)
267 goto scan_error;
269 /* drop clean flag to allow roll-forward and recovery */
270 nilfs->ns_mount_state &= ~NILFS_VALID_FS;
271 valid_fs = 0;
273 err = nilfs_search_super_root(nilfs, &ri);
274 if (err)
275 goto scan_error;
278 err = nilfs_load_super_root(nilfs, sb, ri.ri_super_root);
279 if (unlikely(err)) {
280 printk(KERN_ERR "NILFS: error loading super root.\n");
281 goto failed;
284 if (valid_fs)
285 goto skip_recovery;
287 if (s_flags & MS_RDONLY) {
288 __u64 features;
290 if (nilfs_test_opt(nilfs, NORECOVERY)) {
291 printk(KERN_INFO "NILFS: norecovery option specified. "
292 "skipping roll-forward recovery\n");
293 goto skip_recovery;
295 features = le64_to_cpu(nilfs->ns_sbp[0]->s_feature_compat_ro) &
296 ~NILFS_FEATURE_COMPAT_RO_SUPP;
297 if (features) {
298 printk(KERN_ERR "NILFS: couldn't proceed with "
299 "recovery because of unsupported optional "
300 "features (%llx)\n",
301 (unsigned long long)features);
302 err = -EROFS;
303 goto failed_unload;
305 if (really_read_only) {
306 printk(KERN_ERR "NILFS: write access "
307 "unavailable, cannot proceed.\n");
308 err = -EROFS;
309 goto failed_unload;
311 sb->s_flags &= ~MS_RDONLY;
312 } else if (nilfs_test_opt(nilfs, NORECOVERY)) {
313 printk(KERN_ERR "NILFS: recovery cancelled because norecovery "
314 "option was specified for a read/write mount\n");
315 err = -EINVAL;
316 goto failed_unload;
319 err = nilfs_salvage_orphan_logs(nilfs, sb, &ri);
320 if (err)
321 goto failed_unload;
323 down_write(&nilfs->ns_sem);
324 nilfs->ns_mount_state |= NILFS_VALID_FS; /* set "clean" flag */
325 err = nilfs_cleanup_super(sb);
326 up_write(&nilfs->ns_sem);
328 if (err) {
329 printk(KERN_ERR "NILFS: failed to update super block. "
330 "recovery unfinished.\n");
331 goto failed_unload;
333 printk(KERN_INFO "NILFS: recovery complete.\n");
335 skip_recovery:
336 nilfs_clear_recovery_info(&ri);
337 sb->s_flags = s_flags;
338 return 0;
340 scan_error:
341 printk(KERN_ERR "NILFS: error searching super root.\n");
342 goto failed;
344 failed_unload:
345 iput(nilfs->ns_cpfile);
346 iput(nilfs->ns_sufile);
347 iput(nilfs->ns_dat);
349 failed:
350 nilfs_clear_recovery_info(&ri);
351 sb->s_flags = s_flags;
352 return err;
355 static unsigned long long nilfs_max_size(unsigned int blkbits)
357 unsigned int max_bits;
358 unsigned long long res = MAX_LFS_FILESIZE; /* page cache limit */
360 max_bits = blkbits + NILFS_BMAP_KEY_BIT; /* bmap size limit */
361 if (max_bits < 64)
362 res = min_t(unsigned long long, res, (1ULL << max_bits) - 1);
363 return res;
366 static int nilfs_store_disk_layout(struct the_nilfs *nilfs,
367 struct nilfs_super_block *sbp)
369 if (le32_to_cpu(sbp->s_rev_level) < NILFS_MIN_SUPP_REV) {
370 printk(KERN_ERR "NILFS: unsupported revision "
371 "(superblock rev.=%d.%d, current rev.=%d.%d). "
372 "Please check the version of mkfs.nilfs.\n",
373 le32_to_cpu(sbp->s_rev_level),
374 le16_to_cpu(sbp->s_minor_rev_level),
375 NILFS_CURRENT_REV, NILFS_MINOR_REV);
376 return -EINVAL;
378 nilfs->ns_sbsize = le16_to_cpu(sbp->s_bytes);
379 if (nilfs->ns_sbsize > BLOCK_SIZE)
380 return -EINVAL;
382 nilfs->ns_inode_size = le16_to_cpu(sbp->s_inode_size);
383 nilfs->ns_first_ino = le32_to_cpu(sbp->s_first_ino);
385 nilfs->ns_blocks_per_segment = le32_to_cpu(sbp->s_blocks_per_segment);
386 if (nilfs->ns_blocks_per_segment < NILFS_SEG_MIN_BLOCKS) {
387 printk(KERN_ERR "NILFS: too short segment.\n");
388 return -EINVAL;
391 nilfs->ns_first_data_block = le64_to_cpu(sbp->s_first_data_block);
392 nilfs->ns_nsegments = le64_to_cpu(sbp->s_nsegments);
393 nilfs->ns_r_segments_percentage =
394 le32_to_cpu(sbp->s_r_segments_percentage);
395 nilfs->ns_nrsvsegs =
396 max_t(unsigned long, NILFS_MIN_NRSVSEGS,
397 DIV_ROUND_UP(nilfs->ns_nsegments *
398 nilfs->ns_r_segments_percentage, 100));
399 nilfs->ns_crc_seed = le32_to_cpu(sbp->s_crc_seed);
400 return 0;
403 static int nilfs_valid_sb(struct nilfs_super_block *sbp)
405 static unsigned char sum[4];
406 const int sumoff = offsetof(struct nilfs_super_block, s_sum);
407 size_t bytes;
408 u32 crc;
410 if (!sbp || le16_to_cpu(sbp->s_magic) != NILFS_SUPER_MAGIC)
411 return 0;
412 bytes = le16_to_cpu(sbp->s_bytes);
413 if (bytes > BLOCK_SIZE)
414 return 0;
415 crc = crc32_le(le32_to_cpu(sbp->s_crc_seed), (unsigned char *)sbp,
416 sumoff);
417 crc = crc32_le(crc, sum, 4);
418 crc = crc32_le(crc, (unsigned char *)sbp + sumoff + 4,
419 bytes - sumoff - 4);
420 return crc == le32_to_cpu(sbp->s_sum);
423 static int nilfs_sb2_bad_offset(struct nilfs_super_block *sbp, u64 offset)
425 return offset < ((le64_to_cpu(sbp->s_nsegments) *
426 le32_to_cpu(sbp->s_blocks_per_segment)) <<
427 (le32_to_cpu(sbp->s_log_block_size) + 10));
430 static void nilfs_release_super_block(struct the_nilfs *nilfs)
432 int i;
434 for (i = 0; i < 2; i++) {
435 if (nilfs->ns_sbp[i]) {
436 brelse(nilfs->ns_sbh[i]);
437 nilfs->ns_sbh[i] = NULL;
438 nilfs->ns_sbp[i] = NULL;
443 void nilfs_fall_back_super_block(struct the_nilfs *nilfs)
445 brelse(nilfs->ns_sbh[0]);
446 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
447 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
448 nilfs->ns_sbh[1] = NULL;
449 nilfs->ns_sbp[1] = NULL;
452 void nilfs_swap_super_block(struct the_nilfs *nilfs)
454 struct buffer_head *tsbh = nilfs->ns_sbh[0];
455 struct nilfs_super_block *tsbp = nilfs->ns_sbp[0];
457 nilfs->ns_sbh[0] = nilfs->ns_sbh[1];
458 nilfs->ns_sbp[0] = nilfs->ns_sbp[1];
459 nilfs->ns_sbh[1] = tsbh;
460 nilfs->ns_sbp[1] = tsbp;
463 static int nilfs_load_super_block(struct the_nilfs *nilfs,
464 struct super_block *sb, int blocksize,
465 struct nilfs_super_block **sbpp)
467 struct nilfs_super_block **sbp = nilfs->ns_sbp;
468 struct buffer_head **sbh = nilfs->ns_sbh;
469 u64 sb2off = NILFS_SB2_OFFSET_BYTES(nilfs->ns_bdev->bd_inode->i_size);
470 int valid[2], swp = 0;
472 sbp[0] = nilfs_read_super_block(sb, NILFS_SB_OFFSET_BYTES, blocksize,
473 &sbh[0]);
474 sbp[1] = nilfs_read_super_block(sb, sb2off, blocksize, &sbh[1]);
476 if (!sbp[0]) {
477 if (!sbp[1]) {
478 printk(KERN_ERR "NILFS: unable to read superblock\n");
479 return -EIO;
481 printk(KERN_WARNING
482 "NILFS warning: unable to read primary superblock "
483 "(blocksize = %d)\n", blocksize);
484 } else if (!sbp[1]) {
485 printk(KERN_WARNING
486 "NILFS warning: unable to read secondary superblock "
487 "(blocksize = %d)\n", blocksize);
491 * Compare two super blocks and set 1 in swp if the secondary
492 * super block is valid and newer. Otherwise, set 0 in swp.
494 valid[0] = nilfs_valid_sb(sbp[0]);
495 valid[1] = nilfs_valid_sb(sbp[1]);
496 swp = valid[1] && (!valid[0] ||
497 le64_to_cpu(sbp[1]->s_last_cno) >
498 le64_to_cpu(sbp[0]->s_last_cno));
500 if (valid[swp] && nilfs_sb2_bad_offset(sbp[swp], sb2off)) {
501 brelse(sbh[1]);
502 sbh[1] = NULL;
503 sbp[1] = NULL;
504 swp = 0;
506 if (!valid[swp]) {
507 nilfs_release_super_block(nilfs);
508 printk(KERN_ERR "NILFS: Can't find nilfs on dev %s.\n",
509 sb->s_id);
510 return -EINVAL;
513 if (!valid[!swp])
514 printk(KERN_WARNING "NILFS warning: broken superblock. "
515 "using spare superblock (blocksize = %d).\n", blocksize);
516 if (swp)
517 nilfs_swap_super_block(nilfs);
519 nilfs->ns_sbwcount = 0;
520 nilfs->ns_sbwtime = le64_to_cpu(sbp[0]->s_wtime);
521 nilfs->ns_prot_seq = le64_to_cpu(sbp[valid[1] & !swp]->s_last_seq);
522 *sbpp = sbp[0];
523 return 0;
527 * init_nilfs - initialize a NILFS instance.
528 * @nilfs: the_nilfs structure
529 * @sb: super block
530 * @data: mount options
532 * init_nilfs() performs common initialization per block device (e.g.
533 * reading the super block, getting disk layout information, initializing
534 * shared fields in the_nilfs).
536 * Return Value: On success, 0 is returned. On error, a negative error
537 * code is returned.
539 int init_nilfs(struct the_nilfs *nilfs, struct super_block *sb, char *data)
541 struct nilfs_super_block *sbp;
542 int blocksize;
543 int err;
545 down_write(&nilfs->ns_sem);
547 blocksize = sb_min_blocksize(sb, NILFS_MIN_BLOCK_SIZE);
548 if (!blocksize) {
549 printk(KERN_ERR "NILFS: unable to set blocksize\n");
550 err = -EINVAL;
551 goto out;
553 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
554 if (err)
555 goto out;
557 err = nilfs_store_magic_and_option(sb, sbp, data);
558 if (err)
559 goto failed_sbh;
561 err = nilfs_check_feature_compatibility(sb, sbp);
562 if (err)
563 goto failed_sbh;
565 blocksize = BLOCK_SIZE << le32_to_cpu(sbp->s_log_block_size);
566 if (blocksize < NILFS_MIN_BLOCK_SIZE ||
567 blocksize > NILFS_MAX_BLOCK_SIZE) {
568 printk(KERN_ERR "NILFS: couldn't mount because of unsupported "
569 "filesystem blocksize %d\n", blocksize);
570 err = -EINVAL;
571 goto failed_sbh;
573 if (sb->s_blocksize != blocksize) {
574 int hw_blocksize = bdev_logical_block_size(sb->s_bdev);
576 if (blocksize < hw_blocksize) {
577 printk(KERN_ERR
578 "NILFS: blocksize %d too small for device "
579 "(sector-size = %d).\n",
580 blocksize, hw_blocksize);
581 err = -EINVAL;
582 goto failed_sbh;
584 nilfs_release_super_block(nilfs);
585 sb_set_blocksize(sb, blocksize);
587 err = nilfs_load_super_block(nilfs, sb, blocksize, &sbp);
588 if (err)
589 goto out;
590 /* not failed_sbh; sbh is released automatically
591 when reloading fails. */
593 nilfs->ns_blocksize_bits = sb->s_blocksize_bits;
594 nilfs->ns_blocksize = blocksize;
596 get_random_bytes(&nilfs->ns_next_generation,
597 sizeof(nilfs->ns_next_generation));
599 err = nilfs_store_disk_layout(nilfs, sbp);
600 if (err)
601 goto failed_sbh;
603 sb->s_maxbytes = nilfs_max_size(sb->s_blocksize_bits);
605 nilfs->ns_mount_state = le16_to_cpu(sbp->s_state);
607 err = nilfs_store_log_cursor(nilfs, sbp);
608 if (err)
609 goto failed_sbh;
611 set_nilfs_init(nilfs);
612 err = 0;
613 out:
614 up_write(&nilfs->ns_sem);
615 return err;
617 failed_sbh:
618 nilfs_release_super_block(nilfs);
619 goto out;
622 int nilfs_discard_segments(struct the_nilfs *nilfs, __u64 *segnump,
623 size_t nsegs)
625 sector_t seg_start, seg_end;
626 sector_t start = 0, nblocks = 0;
627 unsigned int sects_per_block;
628 __u64 *sn;
629 int ret = 0;
631 sects_per_block = (1 << nilfs->ns_blocksize_bits) /
632 bdev_logical_block_size(nilfs->ns_bdev);
633 for (sn = segnump; sn < segnump + nsegs; sn++) {
634 nilfs_get_segment_range(nilfs, *sn, &seg_start, &seg_end);
636 if (!nblocks) {
637 start = seg_start;
638 nblocks = seg_end - seg_start + 1;
639 } else if (start + nblocks == seg_start) {
640 nblocks += seg_end - seg_start + 1;
641 } else {
642 ret = blkdev_issue_discard(nilfs->ns_bdev,
643 start * sects_per_block,
644 nblocks * sects_per_block,
645 GFP_NOFS, 0);
646 if (ret < 0)
647 return ret;
648 nblocks = 0;
651 if (nblocks)
652 ret = blkdev_issue_discard(nilfs->ns_bdev,
653 start * sects_per_block,
654 nblocks * sects_per_block,
655 GFP_NOFS, 0);
656 return ret;
659 int nilfs_count_free_blocks(struct the_nilfs *nilfs, sector_t *nblocks)
661 unsigned long ncleansegs;
663 down_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
664 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
665 up_read(&NILFS_MDT(nilfs->ns_dat)->mi_sem);
666 *nblocks = (sector_t)ncleansegs * nilfs->ns_blocks_per_segment;
667 return 0;
670 int nilfs_near_disk_full(struct the_nilfs *nilfs)
672 unsigned long ncleansegs, nincsegs;
674 ncleansegs = nilfs_sufile_get_ncleansegs(nilfs->ns_sufile);
675 nincsegs = atomic_read(&nilfs->ns_ndirtyblks) /
676 nilfs->ns_blocks_per_segment + 1;
678 return ncleansegs <= nilfs->ns_nrsvsegs + nincsegs;
681 struct nilfs_root *nilfs_lookup_root(struct the_nilfs *nilfs, __u64 cno)
683 struct rb_node *n;
684 struct nilfs_root *root;
686 spin_lock(&nilfs->ns_cptree_lock);
687 n = nilfs->ns_cptree.rb_node;
688 while (n) {
689 root = rb_entry(n, struct nilfs_root, rb_node);
691 if (cno < root->cno) {
692 n = n->rb_left;
693 } else if (cno > root->cno) {
694 n = n->rb_right;
695 } else {
696 atomic_inc(&root->count);
697 spin_unlock(&nilfs->ns_cptree_lock);
698 return root;
701 spin_unlock(&nilfs->ns_cptree_lock);
703 return NULL;
706 struct nilfs_root *
707 nilfs_find_or_create_root(struct the_nilfs *nilfs, __u64 cno)
709 struct rb_node **p, *parent;
710 struct nilfs_root *root, *new;
712 root = nilfs_lookup_root(nilfs, cno);
713 if (root)
714 return root;
716 new = kmalloc(sizeof(*root), GFP_KERNEL);
717 if (!new)
718 return NULL;
720 spin_lock(&nilfs->ns_cptree_lock);
722 p = &nilfs->ns_cptree.rb_node;
723 parent = NULL;
725 while (*p) {
726 parent = *p;
727 root = rb_entry(parent, struct nilfs_root, rb_node);
729 if (cno < root->cno) {
730 p = &(*p)->rb_left;
731 } else if (cno > root->cno) {
732 p = &(*p)->rb_right;
733 } else {
734 atomic_inc(&root->count);
735 spin_unlock(&nilfs->ns_cptree_lock);
736 kfree(new);
737 return root;
741 new->cno = cno;
742 new->ifile = NULL;
743 new->nilfs = nilfs;
744 atomic_set(&new->count, 1);
745 atomic_set(&new->inodes_count, 0);
746 atomic_set(&new->blocks_count, 0);
748 rb_link_node(&new->rb_node, parent, p);
749 rb_insert_color(&new->rb_node, &nilfs->ns_cptree);
751 spin_unlock(&nilfs->ns_cptree_lock);
753 return new;
756 void nilfs_put_root(struct nilfs_root *root)
758 if (atomic_dec_and_test(&root->count)) {
759 struct the_nilfs *nilfs = root->nilfs;
761 spin_lock(&nilfs->ns_cptree_lock);
762 rb_erase(&root->rb_node, &nilfs->ns_cptree);
763 spin_unlock(&nilfs->ns_cptree_lock);
764 if (root->ifile)
765 iput(root->ifile);
767 kfree(root);